AUCKLAND, New Zealand --There will be just one American team left in the America's Cup at the end of the semifinal repechage between Oracle BMW Racing and OneWorld, beginning on Friday.

The all-U.S. pairing pitches West Coast billionaires against each other with Larry Ellison's $90 million San Francisco Oracle team racing Craig McCaw and Paul Allen's $75 million Seattle OneWorld team.

The repechage winner will face Swiss team Alinghi in the final beginning on January 11, with the Louis Vuitton Cup winner going on to challenge Team New Zealand for the America's Cup in February.

The series was originally a best of seven with the first team to win four races going through, but OneWorld entered the semifinal with a one-point penalty imposed by Cup organisers for having design information belonging to other teams, so it has to win five races to go through.

Oracle BMW enters the match after a 4-0 loss to Alinghi in the semifinals, while OneWorld comes in having defeated and eliminated Prada -- the defending Louis Vuitton Cup champions.

Oracle BMW is the favourite with a 5-1 lead in the six meetings so far with OneWorld.

Since the end of the round robins, Oracle BMW has had the upper hand beating OneWorld by 4-0 in the quarterfinal with an average time difference of 20 seconds.

However, OneWorld skipper Peter Gilmour says they are ready for the rematch: "We learned a lesson there. I think we're in better shape now."

Both teams will be racing the same boats they raced in the semifinals with OneWorld using USA 67 and Oracle BMW USA 76.

Neither team is expected to use the radical "second skin" appendage that has been seen on one of Team New Zealand's boats and is currently being tested by Alinghi.

However, Oracle did reveal an unusual sail last week that is flown like a kite, high above the mast.

"Our design team has come up with a lot of innovations," Oracle navigator Ian Burns said. "This is on the edge of innovation. Anyone who's flown a kite of that type knows there's a big advantage to having something of that nature."

Team New Zealand sail designer Burns Fallow agreed the sail could have some merit: "We've had days on the Hauraki Gulf when there's almost no wind on the water, but at 300 to 400 feet (elevation) there's been 20 to 30 knots.

"So there are obvious benefits of flying a spinnaker at higher elevation from your masthead."